University School of Physical Education in Wrocław University School of Physical Education in Kraków

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University School of Physical Education in Wrocław

University School of Physical Education in Kraków

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University School of Physical Education in Kraków (Akademia Wychowania Fizycznego im. Bronisława Czecha w Krakowie) Human movement

quarterly

vol. 15, number 4 (December), 2014, pp. 191 – 250 editor-in-Chief alicja Rutkowska-Kucharska

University School of Physical Education, Wrocław, Poland associate editor edward mleczko

University School of Physical Education, Kraków, Poland editorial Board

Physical activity, fitness and health

Wiesław Osiński University School of Physical Education, Poznań, Poland Applied sport sciences

Zbigniew Trzaskoma Józef Piłsudski University of Physical Education, Warszawa, Poland Biomechanics and motor control

Tadeusz Bober University School of Physical Education, Wrocław, Poland Kornelia Kulig University of Southern California, Los Angeles, USA Physiological aspects of sports

Andrzej Suchanowski Józef Rusiecki Olsztyn University College, Olsztyn, Poland Psychological diagnostics of sport and exercise

Andrzej Szmajke Opole University, Opole, Poland advisory Board

Wojtek J. Chodzko-Zajko University of Illinois, Urbana, Illinois, USA Gudrun Doll-Tepper Free University, Berlin, Germany

Józef Drabik University School of Physical Education and Sport, Gdańsk, Poland Kenneth Hardman University of Worcester, Worcester, United Kingdom

Andrew Hills Queensland University of Technology, Queensland, Australia Zofia Ignasiak University School of Physical Education, Wrocław, Poland Slobodan Jaric University of Delaware, Newark, Delaware, USA

Toivo Jurimae University of Tartu, Tartu, Estonia

Han C.G. Kemper Vrije University, Amsterdam, The Netherlands

Wojciech Lipoński University School of Physical Education, Poznań, Poland Gabriel Łasiński University School of Physical Education, Wrocław, Poland Robert M. Malina University of Texas, Austin, Texas, USA

Melinda M. Manore Oregon State University, Corvallis, Oregon, USA Philip E. Martin Iowa State University, Ames, Iowa, USA Joachim Mester German Sport University, Cologne, Germany Toshio Moritani Kyoto University, Kyoto, Japan

Andrzej Pawłucki University School of Physical Education, Wrocław, Poland John S. Raglin Indiana University, Bloomington, Indiana, USA

Roland Renson Catholic University, Leuven, Belgium

Tadeusz Rychlewski University School of Physical Education, Poznań, Poland James F. Sallis San Diego State University, San Diego, California, USA James S. Skinner Indiana University, Bloomington, Indiana, USA Jerry R. Thomas University of North Texas, Denton, Texas, USA Karl Weber German Sport University, Cologne, Germany Peter Weinberg Hamburg, Germany

Marek Woźniewski University School of Physical Education, Wrocław, Poland Guang Yue Cleveland Clinic Foundation, Cleveland, Ohio, USA

Wladimir M. Zatsiorsky Pennsylvania State University, State College, Pennsylvania, USA Jerzy Żołądź University School of Physical Education, Kraków, Poland

Translation: Michael Antkowiak, Tomasz Skirecki Design: Agnieszka Nyklasz

Copy editor: Beata Irzykowska Statistical editor: Małgorzata Kołodziej

Indexed in: SPORTDiscus, Index Copernicus, Altis, Sponet, Scopus, CAB Abstracts, Global Health 7 pkt wg rankingu Ministerstwa Nauki i Szkolnictwa Wyższego

http://156.17.111.99/hum_mov Editorial Office Dominika Niedźwiedź

51-612 Wrocław, al. Ignacego Jana Paderewskiego 35, Poland, tel. 48 71 347 30 51, hum_mov@awf.wroc.pl This is to certify the conformity with PN-EN-ISO 9001:2009

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EDiTORiAL

We would like to express our deepest gratitude to all Reviewers for their most effective contribution to improvement of quality of Human Movement in 2014:

2014, vol. 15 (4)

Marianna Barlak, Warszawa (Poland) Tadeusz Bober, Wrocław (Poland) Michał Bronikowski, Poznań (Poland) Anna Burdukiewicz, Wrocław (Poland) Kamila czajka, Wrocław (Poland) Jacek Dembiński, Wrocław (Poland) Henryk Duda, Kraków (Poland) Abbigail L. Fietzer, Los Angeles (UsA) sean Flanagan, Los Angeles (UsA) Jan Gajewski, Warszawa (Poland) Rami Hashish, Los Angeles (UsA) Janusz iskra, Katowice (Poland) Zygfryd Juczyński, Bydgoszcz (Poland) Grzegorz Juras, Katowice (Poland) Adam Kantanista, Poznań (Poland) Adam Kawczyński, Wrocław (Poland) Tadeusz Koszczyc, Wrocław (Poland) Magdalena Król-Zielińska, Poznań (Poland) Magdalena Krzykała, Poznań (Poland) Michał Kuczyński, Wrocław (Poland) Lesław Kulmatycki, Wrocław (Poland) Janusz Maciaszek, Poznań (Poland) Waldemar Mieszała, Wrocław (Poland) Edward Mleczko, Kraków (Poland)

Bartosz Molik, Warszawa (Poland) Wiesław Osiński, Poznań (Poland) Beata Pluta, Poznań (Poland)

John M. Popovich, East Lansing (UsA)

Miroslava Pridalova, Olomouc (czech Republic) Danuta Pupek-Musialik, Poznań (Poland) Jerzy sadowski, Biała Podlaska (Poland) Tomasz sahaj, Poznań (Poland)

sachithra samarawickrame, Los Angeles (UsA) Adam siemieński, Wrocław (Poland)

Teresa sławińska-Ochla, Wrocław (Poland)

Małgorzata słowińska-Lisowska, Wrocław (Poland) Aleksandra stachoń, Wrocław (Poland)

Rafał stemplewski, Poznań (Poland) Helena stokłosa, Katowice (Poland) Robert szeklicki, Poznań (Poland) Maciej Tomczak, Poznań (Poland) Aleksander Tyka, Kraków (Poland) sławomir Winiarski, Wrocław (Poland) Barbara Woynarowska, Warszawa (Poland) Jacek Zieliński, Poznań (Poland)

Ewa Ziółkowska-Łajp, Poznań (Poland) stanisław Żak, Kraków (Poland)

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Body poSTurE in young woMEn involvEd

in rEgulAr AEroBiC ExErCiSE

JuSTynA drzAł-grABiEC 1_,_{AlEkSAndrA TruSzCzyńSkA}2 _* 1_{University of Rzeszów, Rzeszów, Poland}

2_{Józef Piłsudski University of Physical Education, Warsaw, Poland}

ABsTRAcT

Purpose. The aim of the study was an assessment of posture in women who regularly perform aerobic exercise. Methods. The study group consisted of 50 women actively participating in aerobics classes (mean: age 28.64 ± 5.3 years, body mass 59.83 ± 6.7 kg, height 167.75 ± 4.9 cm, BMi 21.24 ± 3.6 m/kg2_{) and a control group of 50 women not involved in any regular physical activity} (mean: age 28.55 ± 5.05 years, body mass 62.47 ± 10.5 kg, height 167.74 ± 4.8 cm, BMi 22.26 ± 4.8 m/kg2_{). All participants} were subjected to a photogrammetric assessment of posture. Results. statistically significant differences in posture were identified between the two groups for lumbarosacral and thoracolumbar spinal curvatures. Conclusions. Women who regularly perform aerobic exercise present greater thoracic kyphosis and shoulder asymmetry than women not involved in aerobics.

Key words: aerobic exercise, body posture, photogrammetry, women, spine doi: 10.1515/humo-2015-0010

2014, vol. 15 (4), 195– 198

* corresponding author.

Introduction

Aerobic exercise as a form of physical activity is con-tinuously developing. Mass media has encouraged this form of exercise to society, touting its positive effects on health and fitness. A lot of such information, however, is not entirely based on scientifically-proven facts but in-stead guided by marketing strategies. scientific research to date has analysed some of the effects of such physical activity on the body. The literature indicates that the benefits of regular aerobics exercise include an increase in muscular strength, endurance, and coordination [1] as well as better intervertebral disc nutrition, better back pain prevention, and improved physical and mental con-dition [2]. Although studies such forms of exercise as Pi-lates, stretching, or weight training on individuals with postural disorders have shown improved postural con-trol and reduced pain [3–5], the effects of regular aerobics exercise on body posture have yet to be studied. There-fore, the aim of the study was an assessment of posture in women who regularly perform aerobic exercise.

Material and methods

The study group involved 50 women (mean: age 28.64 ± 5.3 years, body mass 59.83 ± 6.7 kg, height 167.75 ± 4.9 cm, BMi 21.24 ± 3.6 m/kg2_{) who had been practicing} aerobics regularly (two to three times per week) for at least 5 years. All participants attended classes in the same

high quality fitness centre located in Warsaw, Poland by certified aerobics instructors holding degrees in physical education or sport. The control group consisted of 50 women (mean: age 28.55 ± 5.05 years, body mass 62.47 ± 10.5 kg, height 167.74 ± 4.8 cm, BMi 22.26 ± 4.8 m/kg2_{) not involved in any regular physical activity.}

criteria for inclusion in the study were informed con-sent to participate in the study and, for the study group, active, regular and continuing participation in aerobic classes. Exclusion criteria were any acute or recent in-juries and orthopaedic or neurologic disorders. Ethical approval was obtained by the Bioethics committee of the Medical Faculty at the University of Rzeszów, Poland. The authors declare no conflict of interest.

All participants were subjected to a photogrammetric assessment of posture, which involved photo-based anthropometric measurement of the back using equip-ment from cQ Elektronik system [6]. This method pro-vides a spatial (three-dimensional) image by using projec-tion equipment to displays lines on a patient’s back. The lines deform when they are projected on a patient’s back at a specific angle. These line deformations are dependent on how close or far away a reference marker is from the equipment and are registered by a computer, which uses numerical algorithms to generate a contour map of the back.

Analysis of the photograms involved calculating the following angular measures (an illustration of how these parameters were measured is shown in Figure 1):

ALPHA – lumbosacral spinal curvature calculated between the s1 and apex of lordosis,

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J. Drzał-Grabiec, A. Truszczyńska, Body posture in women

BETA – thoracolumbar spinal curvature calculated between the transition from lordotic and kyphotic curves (at maximum kyphosis),

GAMMA – thoracic spinal curvature calculated between the c7 and apex of kyphosis,

KKP – thoracic kyphosis angle calculated as 180° – (BETA + GAMMA),

GKP – depth of thoracic kyphosis calculated between the apex of kyphosis and transition from kyphosis to lordosis,

KLL –lumbar lordosis angle calculated as 180° – (ALPHA + BETA),

GLL – depth of lumbar lordosis calculated between the transition from kyphosis to lordosis and apex of lordosis,

KLB – angle of shoulder asymmetry.

Differences between the means of the two groups were analysed with the use of student’s t for inde-pendent samples. Additional analysis was limited meas-ures with statistically significant differences at p < 0.05. As the variance in the compared groups could be con-sidered homogenous (established with the Levene’s test), student’s original t test with the assumption of equality of variance was used to compare the means. All calculations were performed with sPss ver. 8.0 (iBM, UsA).

Results

The mean values of the analysed measures of pos-ture are presented in Table 1. statistically significant differences were found between the two groups were found for ALPHA and BETA, indicating that lumbaro-sacral (p = 0.044) and thoracolumbar (p = 0.000) spinal curvatures were significantly greater in the control group (Table 2). The posture of women involved in aerobic exercise showed significantly deeper thoracic kyphosis (p = 0.000) and greater shoulder asymmetry (p = 0.004). The remaining measures did not reveal any statistically significant differences.

Discussion

The results revealed an increased lumbosacral angle and decreased thoracolumbar angle in women who per-formed aerobic exercise. Moreover, the posture of these women showed greater shoulder asymmetry and deepened thoracic kyphosis.

Aerobic exercise is usually conducted in groups. This might have an adverse effect on the quality of exercise and may have lead the participants to adopt poor or in-correct form. The incidence of deepened thoracic ky-phosis may have resulted from assuming incorrect body posture or by overloading. The same may have led to the decrease in thoracolumbar spinal curvature. When com-pared with the control group, the deepened thoracic ky-phosis accompanied with decreased BETA angle in the study group indicates kyphosis of the whole spine. shoul-der asymmetry could have resulted from strengthening exercises performed in these types of classes.

Based on the available literature, no studies to date have assessed body posture in women who regularly per-form aerobic exercise, making it very difficult to compare our results with the findings reported in other studies. However, the beneficial effects of other related forms of physical activity on the body and health have been thoroughly discussed. cruz-Ferreira et al. [7] presented

C7 – spinous process of the seventh cervical vertebra

KP – apex of thoracic kyphosis PL – transition from kyphosis to lordosis LL – apex of lumbar lordosis

S1 – transition from lumbar lordosis to the sacral spinal cord

Table. 2 Differences in body posture between the two groups Levene’s test for homogeneity of variance independent t test of mean differences F p t df p ALPHA (°) 3.870 0.052 –2.043 83 0.044 BETA (°) 0.622 0.433 4.771 83 0.000 GAMMA (°) 1.075 0.303 –0.940 83 0.350 GKP (mm) 2.605 0.110 8.269 83 0.000 KLL (°) 11.849 0.001 –1.615 83 0.110 GLL (mm) 2.325 0.131 –0.877 83 0.383 KLB (°) 0.063 0.802 3.001 83 0.004

Table 1. Results of the photogrammetric assessment Measures study group control group

SD SD ALPHA (°) 19.42 26.10 31.37 27.03 BETA (°) 9.02 2.56 4.10 5.77 GAMMA (°) 24.61 24.15 29.39 22.48 GKP (mm) 19.11 7.90 2.92 9.58 KLL (°) 180.58 31.85 193.40 38.95 GLL (mm) –20.32 6.53 –15.06 35.47 KLB (°) 4.16 8.85 –1.65 8.79

Figure 1. illustration of analyzed postural measures how analyzed

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J. Drzał-Grabiec, A. Truszczyńska, Body posture in women

the effects of Pilates exercises in women, finding an im-provement in some of the postural alignment measures (frontal alignment of the shoulder and sagittal align-ment of the head and pelvis). This group suggested that the significant improvement in the sagittal alignment of the head may imply that 6 months of Pilates-based exercise can enhance sagittal alignment of the cervical or thoracic spine.

in turn, physical exercise, mainly in the form of re-sistance training, has led to increased muscle mass and also increased bone mineral density in postmenopausal women [8]. Physical activity has also been recommended as a form of rehabilitation for and in the prevention of low back pain [9]. Other studies determined that a high level of physical fitness is related to a decreased inci-dence of spine-related pain [10].

Other exercise-based interventions resulted in sig-nificant improvements in range of motion and body posture and significant decreases in low back pain. The functional ability of patients in everyday activities of life improved as well [11]. several studies were conducted on the effects of various forms of dance in patients suf-fering from Parkinson’s disease, showing an increase in the quality of life of patients who did dance [12]. The relevant literature reveals a wide spectrum of beneficial effects resulting from physical activity both in healthy individuals and patients with health conditions. The need for additional research on the posture of individuals performing particular forms of physical activity appears to be necessary in order to determine recommendations for and against participation in certain sports and forms of physical activity. in light of the present study, a pos-tural assessment of women who perform aerobic exer-cise including comparisons with a control group could help determine what types of body posture would or would not benefit from aerobics. Based on the results of the present study, particular attention should be paid to the prevention of exaggerated thoracic kyphosis and kyphosis of the whole spine. On this basis, the results indicate that aerobic exercise is suitable for individuals with decreased thoracic kyphosis whereas those with kyphosis or kyphoscoliosis should avoid this form of exercise. instead, it is recommended that this popula-tion should be involved in individual training target-ing particular disorders that, for example, involve re-laxing and stretching exercises. such exercises should be conducted in isolated and spine-relieving positions. current research has shown that body posture corre-lates with spinal disc disorder, which confirms the im-portance of the issue studied herein [13] and also indi-cates the need for additional study on this issue.

The results of the present study also point to the im-portance of monitoring body posture throughout the physical training process. This should be one of the responsibilities of aerobics instructors, where, apart from

explaining the aim and execution of a particular exer-cise, should also educate participants on the ergonomics of maintaining correct posture during training and pro-vide exercises strengthening proper posture habits.

considering the limitations of the present study, it would be useful to broaden the scope of the study by in-corporating individuals from different age groups as well as assess the effects of aerobic exercise on body posture pre- and post-intervention.

Conclusions

The results indicate statistically significant differences between the study and control groups, where women who regularly perform aerobic exercise present greater thoracic kyphosis and shoulder asymmetry than women not involved in aerobics

References

1. Donath L., Roth R., Hohn Y., Zahner L., Faude O., The ef-fects of Zumba training on cardiovascular and neuromus-cular function in female college students. Eur J Sport Sci, 2014, 14 (6), 569–577, doi: 10.1080/17461391.2013.866168. 2. Prouty J., Fitness fact or fitness fad. ACSMS Health Fit J,

1999, 3 (6), 35, doi: 10.1249/00135124-199911000-00011. 3. Da Fonseca J.L., Magini M., de Freitas T.H., Laboratory

gait analysis in patients with low back pain before and after Pilates intervention. J Sport Rehabil, 2009, 18 (2), 269–282.

4. Kluemper M., Uhl T.L., Hazelrigg H., Effect of stretching and strengthening shoulder muscles on forward shoulder posture in competitive swimmers. J Sport Rehabil, 2006, 15 (1), 58–70.

5. sculco A.D., Paup D.c., Fernhall B., sculco M.J., Effects of aerobic exercise on low back pain patients in treat-ment. Spine J, 2001, 1 (2), 95–101, doi: 10.1016/s1529-9430(01)00026-2.

6. Drzał-Grabiec J., snela s., The influence of rural envi-ronment on body posture. Ann Agric Environ Med, 2012, 19 (4), 846–850.

7. cruz-Ferreira A., Fernandes J., Kuo Y.L., Bernardo L.M., Fernandes O., Laranjo L. et al., Does pilates-based exercise improve postural alignment in adult women? Women Health, 2013, 53 (6), 597–611, doi: 10.1080/03630242.2013.817505. 8. Nelson M.E., Fiatarone M.A., Morganti c.M., Trice i., Green-berg R.A., Evans W.J., Effects of high-intensity strength training on multiple risk factors for osteoporotic frac-tures. A randomized controlled trial. JAMA, 1994, 272 (24), 1909–1914, doi: 10.1001/jama.1994.03520240037038. 9. Krismer M., van Tulder M., strategies for prevention and

management of musculoskeletal conditions. Low back pain (non-specific). Best Pract Res Clin Rheumatol, 2007, 21 (1), 77–91, doi: 10.1016/j.berh.2006.08.004.

10. Heneweer H., Picavet H.s., staes F., Kiers H., Vanhees L., Physical fitness, rather than self-reported physical activi-ties, is more strongly associated with low back pain: evi-dence from a working population. Eur Spine J, 2012, 21 (7), 1265–1272, doi: 10.1007/s00586-011-2097-7.

11. Dzierżanowski M., Dzierżanowski M., Maćkowiak P., słomko W., Radzimińska A., Kaźmierczak U. et al., The

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fluence of active exercise in low positions on the func-tional condition of the lumbar-sacral segment in patients with discopathy. Adv Clin Exp Med, 2013, 22 (3), 421–430, Available from: http://www.advances.am.wroc.pl/pdf/ 2013/22/3/421.pdf.

12. Batson G., Feasibility of an intensive trial of modern dance for adults with Parkinson Disease. J Evidence-Based Complement Altern Med, 2010, 15 (2), 65–83, doi: 10.1177/1533210110383903.

13. Lee P.J., Lee E.L., Hayes W.c., The ratio of thoracic to lumbar compression force is posture dependent. Ergonomics, 2013, 56 (5), 832–841, doi: 10.1080/00140139.2013.775354. Paper received by the Editor: October 8, 2014 Paper accepted for publication: November 12, 2014

Correspondence address Aleksandra Truszczyńska Wydział Rehabilitacji

Akademia Wychowania Fizycznego Józefa Piłsudskiego

ul. Marymoncka 34 00-968 Warszawa, Poland e-mail: aleksandra.rapala@wp.pl

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EduCATion And ThE prEvEnTion of poSTurAl dEfECTS

doi: 10.1515/humo-2015-0011

2014, vol. 15 (4), 199 – 203

AgniESzkA olChowSkA-koTAlA1 _*_,_{krySTynA ChroMik}2 1_{Wrocław Medical University, Wrocław, Poland}

2_{University school of Physical Education, Wrocław, Poland}

ABsTRAcT

Purpose. The aim of this study was to determine: whether and at what stage of education is proper body posture learned, the inten-tion of young adults to participate in activities teaching proper posture, and the effects of factors related with the said inteninten-tion. Methods. The study involved 430 university students aged 18–24 years. Anthropometric data was collected. Participants com-pleted questionnaires assessing physical activity level (iPAQ) and their intention to participate in extracurricular activities teaching proper posture while sitting or walking, proper running technique, corrective gymnastics, or weight loss exercises. A self-assess-ment of posture, physical fitness, attractiveness, and body satisfaction was also completed. Results. Lower back pain was expe-rienced by 41% of the respondents. Most were taught proper posture-related habits in primary school, followed by secondary school, and then at university. Many students expressed their intention to participate in the extracurricular activities. None of the questionnaire variables were associated with the intention to learn proper walking posture or proper running technique. The intention to participate in classes teaching proper sitting posture was associated with lower back pain in women and low physical activity level in men. in women, a relationship was found between the intention to participate in weight loss exercises and body dissatisfaction, high BMi, and poor self-evaluations of posture and attractiveness. in men, this activity was associated with body dissatisfaction. Conclusions. There is a need for further education on the development of proper postural habits at the university level.

Key words: education, body posture, body satisfaction, BMi

Introduction

Many studies are concerned with self care today. Their authors emphasize the need of increasing physical ac-tivity, paying attention to diet, and maintaining a healthy body weight in all age groups. More and more prevention programs have been introduced to encourage such healthy behavior. This is both due to real-life needs and the in-creasing recognition of the importance of lifestyle on health. increased sedentary behavior has led to people spending large amounts time in a sitting position. Me-chanical equipment, vehicles, and other forms of tech-nology have made life easier at the cost of a lazier and less active population. it can be argued that life in the 21st_{century has begun to deviate from the} evolution-ary path set out for us by nature.

Among the appeals for improved self care, more and more attention is being paid to the development of good posture. incorrect posture in everyday activities of life contributes to back pain, especially in the lower back. Pain in the lumbar region of the spine is a serious prob-lem in developed countries. it is estimated that between 60% and 80% of the population experiences lower back pain at some point in life [1]. To effectively combat this phenomenon, we need to be aware of the relationship between back pain and how everyday activities are

per-formed. We need to know how to properly perform these activities and how to exercise and strengthen associated muscle groups based on adopted kinesitherapeutic prin-ciples. This also includes restoring joint mobility, if im-paired. Although a number of educational programs ad-dressing back pain and proper posture have been enacted in schools, they seem to be insufficient. Recent studies have indicated that an increasing number of children and adolescents experience back pain [2]. interventions in childhood were found to be ineffective [3], hence the need for educating people on how to properly take care of their bodies even at later stages of life. Only such continuing education can consciously change health-related habits. The psychological models used to describe the behavioral changes needed to develop healthy habits often stress the concept of intention. Although several studies found that formulating intention does not ulti-mately lead to behavioral changes [4], it is still a crucial factor in taking action.

Based on the above considerations, the aim of this study was to determine (1) whether and at what stage of education did the participants learn about proper sitting and walking posture and also proper running technique (2) whether young adults are willing to par-ticipate in extracurricular activities aimed at correcting posture in sitting, walking, or running or other health-related goals, and (3) what factors are associated with the intention to participate in the suggested extracur-ricular activities.

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A. Olchowska-Kotala, K. chromik, Education and the prevention of postural defects

Table 1. Descriptive statistics characterizing the respondents (as mean ± SD and percent response)

Women Men BMi 21.78 ± 13.89 23.60 ± 7.15 Underweight 16% 6% Normal 73% 65% Overweight 7% 22% Obese 4% 7% iPAQ PA 3877 ± 3662 5843 ± 4927 Low 8% 3% Average 45% 23% High 47% 74% Posture 3.98 ± 1.34 3.88 ± 1.60 Positive 35% 38% i have no opinion 26% 18% Negative 39% 44% Body satisfaction 4.51 ± 1.33 5.14 ± 1.23 Positive 54% 75% i have no opinion 25% 16% Negative 21% 9% Physical fitness 4.43 ± 1.29 5.37 ± 1.16 Positive 49% 82% i have no opinion 30% 14% Negative 21% 4% Attractiveness 4.51 ± 1.24 5.06 ± 1.21 Positive 53% 68% i have no opinion 28% 25% Negative 19% 7%

The study involved 430 environmental and life science university students aged 18–24 years (309 women and 121 men). Participation in the study was voluntary. Body height and mass were recorded. Participants completed the international Physical Activity Questionnaires (iPAQ), a questionnaire on their intention to participate in extra-curricular activities associated with correcting posture and health, and a self-assessment on posture, physical fitness, body satisfaction, and attractiveness. The study was approved by the local ethics committee and con-ducted in October 2012 during the participants’ physical education classes in accordance with the Declaration of Helsinki.

Anthropometric measurements were made in accord-ance with accepted procedures using calibrated equip-ment; measurement error was limited to 1%. Body mass was measured using a portable seca 761 scale (seca, Ger-many) with an accuracy of 0.1 kg. Body height was measured using a Posturometer s (Posmed, Poland) with an accuracy of 0.1 mm. During measurement the participants stood upright with their feet together and head in the Frankfort horizontal plane while unshod and dressed in gym clothes.

Body mass index (BMi) was calculated by dividing body weight (kg) with body height (m²). BMi [5] was classified into four categories: underweight (< 18.5), nor-mal (18.5–24.9), overweight (25–29.9), and obese (> 30). The Polish version of the iPAQ short Form was ad-ministered [6]. All procedures delineated by the iPAQ scientific committee were followed. Physical activity was estimated based walking and moderate and inten-sive physical activity. Total energy cost and therefore the physical activity level (PA) of each respondent was calculated by multiplying exercise frequency and dura-tion by its corresponding intensity to determine the Meta-bolic Equivalent of Tasks (MET), a metaMeta-bolic measure corresponding to oxygen consumption at rest. The iPAQ describes PA in MET min/week; this value was used to distinguish three levels of intensity: low, moderate, and high. The participants were asked to indicate where (pri-mary school, secondary school, university, at home) they were educated about proper sitting posture, proper walk-ing posture, and proper runnwalk-ing technique. Respondents were allowed to select more than one source.

intention to participate in extracurricular activities was assessed with the question, “Would you like to par-ticipate in extracurricular activities teaching: (a) proper sitting habits, (b) proper walking posture, (c) proper running technique, (d) corrective gymnastics, or (e) weight-loss exercises?” Respondents answered with a “yes” or “no”. information on the incidence of low back pain within the past year was also collected by using a “yes” or “no” question.

Respondents were asked to evaluate their body pos-ture. Responses were ordered on a 7-point scale from 1

(very correct) to 7 (very incorrect). This included a self-assessment of body satisfaction, physical fitness, and attractiveness, where the responses were also scaled using a 7-point scale from 1 (very negative position) to 7 (very positive position). The 7 levels were then simplified into three response categories: “positive”, “i have no opinion”, and “negative”. The response “i have no opinion” was based on a response level 4 as the neutral option; the remaining response levels were accordingly grouped.

statistical analysis was performed with sPss ver. 18 (PAsW, UsA). Descriptive statistics were calculated for all variables. The chi-square test was used to establish any relationships between the intention to participate in the extracurricular activities (on proper posture while sitting, walking, and running; corrective gymnastics; and weight loss) and the questionnaire variables. Analy-ses were performed separately for men and women. sta-tistical significance was set at p 0.05.

Results

As shown in Table 1, the majority of the participants fell within normal ranges. More were underweight than

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Table 2. Prevention of postural defects at different stages of education

stage of education

Proper sitting posture Primary school 87% secondary school 31%

University 14%

Home 84%

Proper walking posture Primary school 70% secondary school 22%

University 7%

Home 75%

Proper running technique Primary school 38% secondary school 33%

University 7%

Home 20%

corrective gymnastics Primary school 57% secondary school 3%

University 2%

Table 4. intention to participate in extracurricular activities among the female respondents (n = 309) BMi

² df(3) PA level² df(2) Posture ² df(6) Back pain² df(1) Physical fitness² df(6) Attractiveness ² df(6) Body satisfaction ² df(6)

sitting 0.633 6.858 8.626 5.916* 4.945 6.095 2.131 Walking 3.048 5.504 5.785 3.163 4.250 2.808 3.839 Running 0.168 0.480 2.389 1.952 7.779 4.617 10.343 corrective gymnastics 4.449 5.192 17.874* 0.728 3.580 4.387 3.293 Weight loss 21.853** 0.492 16.587* 0.216 7.413 15.387* 35.015** * p 0.05, ** p 0.001

Table 5. intention to participate in extracurricular activities among the male respondents (n = 121) BMi

² df(3) ² df(2)PA Posture ² df(6) Back pain² df(1) Physical fitness² df(5) Attractiveness ² df(6) Body satisfaction ² df(5)

sitting 6.146 4.116* 3.179 0.051 6.059 1.218 7.521 Walking 2.488 0.250 1.984 0.155 2.889 3.230 6.000 Running 2.224 0.460 5.105 0.781 3.903 3.237 7.724 corrective gymnastics 10.757* 1.038 2.931 0.130 7.838 7.124 5.805 Weight loss 5.340 1.187 6.730 0.130 7.282 3.565 13.334* * p 0.05

Table 3. intention to participate in extracurricular activities

Extracurricular activity Women Men Proper sitting posture 28% 20% Proper walking posture 39% 32% Proper running technique 38% 39%

corrective gymnastics 35% 25%

Weight loss exercises 62% 28%

obese and overweight combined. Among men, the ma-jority had BMi above 24.9 while only 6% were classi-fied as underweight.

The majority of the respondents indicated that they learned proper posture and running technique in primary school (87% – sitting posture, 70% – walking posture, 38% running technique; Table 2). This was then followed by secondary school (31% – sitting, 22% – walking, 33% – running technique) and then at university (14% – sitting, 7% – walking, 7% – running technique). Approximately 41% of the sample experienced low back pain. corrective gymnastics classes had been attended by 2% of the re-spondents at the university level.

Many of the respondents expressed their intention to participate in the suggested extracurricular activities (Table 3). However, none of the questionnaire variables were associated with the intention to participate in activities teaching proper walking posture or proper running technique (Tables 4 and 5). in women, a relation-ship between the intention to participate in classes on proper sitting posture and lower back pain was found. in men, the intention to participate in classes on proper sitting posture was associated with low PA. A relation-ship was found in women between the intention to participate in weight loss activities and high BMi and a low self-evaluation of body satisfaction, posture, and attractiveness. in men, the intention to participate in weight loss activities was associated only with body dissatisfaction.

Analysis between the women and men on their in-tention to participate in the suggested extracurricular activities showed that significantly more women ex-pressed their intention to take part in activities aimed

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at weight loss, ²(1, n = 424) = 40.563, p = 0.001. slightly more women than men wanted to participate in the posture correction classes, ²(1, n = 423) = 3.395, p = 0.065. There were no differences between the men and women in the intention to participate in the remaining extra-curricular activities.

Discussion

Although a majority of the respondents, both female and male, were found to have normal BMi and above-guideline PA [7], 41% declared they felt lower back pain. Acute pain in the lumbar spine is very common [1], but considering that this result was found in a group of young individuals, 41% is a worrying number. This finding suggests the need for introducing interventions in this population.

The present study examined the prevention of pos-tural defects by considering various aspects that may determine healthy posture in sitting and walking, as these are the most frequently performed activities in the course of the day, and using proper running technique, an in-creasingly popular physical activity among young people. The collected data indicated that information imparting healthy postural habits was most commonly introduced in primary school. Many respondents also indicated their family home as a source of learning proper postural habits. Although proper posture should be established at an early school age [8], not all of the respondents indicated they acquired such knowledge during this period. Thus, due to the high health and economic costs of chronic low back pain [9], education on proper posture habits in every-day activities of life (and preventing spine-related pain) should be continual, from primary school to later edu-cational stages as well as in the workplace [10]. Although not all of respondents declared being taught proper sit-ting and walking habits or correct running technique, this is not indicative that some schools lacked posture-related programs. such information is sometimes con-veyed separately, interwoven in other school activities such as physical education classes. Another explana-tion for these results may also stem from the fact that the respondents did not remember being taught this subject or that not enough emphasis was placed during classes in the prevention of postural disorders.

Not all of the respondents who negatively assessed their body posture wanted to participate in the extracur-ricular activities, such as corrective gymnastics classes. However, the predictors of the intention to participate in this extracurricular were poor self-assessed posture in women and being overweight in men. The results showed that slightly more women than men wanted to partici-pate in corrective gymnastics. The results also suggested that the predictors of the intention to participate in activities on proper sitting posture were taking little physical activity in men and low back pain in women. Although many of the respondents expressed their

in-tention to participate in activities on proper walking posture and proper running technique, none of the ana-lyzed variables were found to determine these intentions. Noteworthy is the fact that a large number of respondents wanted to participate in the suggested activities, indica-tive that young people do recognize the need to improve body image and work on correcting posture. The age range of this sample (university students) is a time when involvement in physical activity switches from habitual to intentional behavior [11]. Therefore, it would worth-while to expand current university-level physical educa-tion classes and place emphasis on proper postural habits. One finding that was not surprising was that wom-en were more willing to participate in weight-loss exer-cises. This has been confirmed in earlier studies, showing higher levels of body dissatisfaction in women than men [12, 13] and is a reflection of the social pressure to be slim [14]. Previous studies have indicated that body mass is a significant contributing factor not only to women’s body image [15] but also self-esteem [16]. The results of our study indicated that the intention to participate in the suggested posture- and health-relat-ed activities among women was higher in those with greater BMi and body dissatisfaction and with a lower opinion of one’s attractiveness or posture. Among men, the intention to participate in weight-loss exercises was not associated with BMi but instead body dissatisfac-tion. The lack of a relationship between the intention to participate in weight-loss exercises and BMi reveals that not all men with above normal BMi wish to participate in such activities. in turn, the number of women who declared their intention to perform weight-loss exercise was much higher than the number of women that who would warrant such exercise as based on their BMi. Nonetheless, the differences between the sexes indicate the need for separate prevention models. in men, this should involve building awareness on maintaining a nor-mal weight to height ratio. interventions aimed at women should instead concentrate on correcting weight-related misconceptions and introduce psychological skills in-creasing body satisfaction levels.

The present study has a number of limitations that require addressing. First, it is subject to self-evaluation and recall biases, where respondents may have consciously or unconsciously misreported data. The potential errors of these methods are well-known [17]. second, the study was correlational in nature, limiting the drawing of any cause-and-effect conclusions.

Conclusions

Based on the fact that a significant number of the respondents experienced low back pain and declared their intention to participate in extracurricular posture- and weight-related activities, additional educational in-terventions at all levels of education are needed to pre-vent the onset of postural disorders. These conclusions,

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similar to those presented elsewhere [18, 19], point to the need for a multi-disciplinary intervention involv-ing physical education teachers and therapists and in-clude the development of posture-related knowledge, beliefs, and habits and include well-thought-out and planned physical activity.

References

1. Anderson L., Educational approaches to management of low back pain. Orthop Nurs, 1989, 8 (1), 43–46

2. calvo-Muñoz i., Gómez-conesa A., sánchez-Meca J., Prevalence of low back pain in children and adolescents: a meta-analysis. BMC Pediatrics, 2013, 13, 14, doi: 10.1186/1471-2431-13-14.

3. Dolphens M., cagnie B., Danneels L., De clercq D., De Bourdeaudhuij i., cardon G., Long-term effectiveness of a back education program in elementary schoolchildren: an 8-year follow-up study. Eur Spine J, 2011, 20 (12), 2134–2142, doi: 10.1007/s00586-011-1856-9.

4. Webb T.L., sheeran P., Luszczynska A., Planning to break unwanted habits: habit strength moderates implementa-tion intenimplementa-tion effects on behavior change. Br J Soc Psychol, 2009, 48 (3), 507–523, doi: 10.1348/014466608X370591. 5. WHO, Obesity: Preventing and managing the global epi-demic. Report of a WHO consultation World Health Organization Technical Report series 2001/03/10 ed. WHO, Geneva 2000, 894, 1–253.

6. Biernat E., stupnicki R., Gajewski A.K., Między naro dowy Kwestionariusz Aktywności Fizycznej (iPAQ) – Polish version. Wychowanie Fizyczne i Sport, 2007, 51 (1), 47–54. 7. Haskell W.L., Lee i.M., Pate R.R., Powell K.E., Blair s.N.,

Franklin B.A. et al., Physical activity and public health: updated recommendation for adults from the American college of sports Medicine and the American Heart As-sociation. Circulation, 2007, 116 (9), 1081–1093, doi: 10.1161/ciRcULATiONAHA.107.185649.

8. Jones G.T., Macfarlane G.J., Predicting persistent low back pain in schoolchildren: a prospective cohort study. Ar-thritis Rheum, 2009, 61 (10), 1359–1366, doi: 10.1002/ art.24696.

9. Andersson G.B.J., Epidemiological features of chronic low-back pain. Lancet, 1999, 354 (9178), 581–585. 10. Burton A.K., Balague F., cardon G., Eriksen H.R.,

Hen-rotin Y., Lahad A. et al., How to prevent low back pain.

Best Pract Res Clin Rheumatol, 2005, 19 (4), 541–555, doi: 10.1016/j.berh.2005.03.001.

11. Wood W., Tam L., Witt M.G., changing circumstances, disrupting habits. J Pers Soc Psychol, 2005, 88 (6), 918–933, doi: 10.1037/0022-3514.88.6.918.

12. Ogden J., Mundray K., The effect of the media o body satisfaction: the role of gender and size. Eur Eat Disord Rev, 1996, 4 (3), 171–182, doi: 10.1002/(sici)1099-0968(199609)4:3<171::AiD-ERV132>3.0.cO;2-U. 13. Olmsted M.P., McFarlane T., Body weight and body image.

BMC Women’s Health, 2004, (suppl 1), s5, doi: 10.1186/1472-6874-4-s1-s5.

14. Monteath s.A., Mccabe M.P., The influence of societal factors on female body image. J Soc Psychol, 1997, 137 (6), 708–727, doi: 10.1080/00224549709595493.

15. Algars M., santtila P., Varjonen M., Witting K., Johans-son A., Jern P. et al., The adult body: How age, gender, and body mass index are related to body image. J Aging Health, 2009, 21 (8), 1112–1132, doi: 10.1177/0898264309348023. 16. Biro F.M., striegel-Moore R.H., Franko D.L., Padgett J.,

Bean J.A., self-esteem in adolescent females. J Adolesc Health, 2006, 39 (4), 501–507, doi:10.1016/j.jado-health.2006.03.010.

17. Maughan B., Rutter M., Retrospective reporting of child-hood adversity: issues in assessing long-term recall. J Pers Disord, 1997, 11 (1), 19–33.

18. Wand B.M., Bird c., McAuley J.H., Dore c.J., MacDow-ell M., De souza L.H., Early intervention for the manage-ment of acute low back pain: a single-blind randomized controlled trial of biopsychosocial education, manual therapy, and exercise. Spine, 2004, 29 (21), 2350–2356. 19. Mendez F.J., Gomez-conesa A., Postural Hygiene Program

to Prevent Low Back Pain. Spine, 2001, 26 (11), 1280–1286. Paper received by the Editor: May 27, 2014

Paper accepted for publication: June 9, 2014 Correspondence address

Agnieszka Olchowska-Kotala

Zakład Humanistycznych Nauk Lekarskich Uniwersytet Medyczny we Wrocławiu ul. Mikulicza-Radeckiego 7

50-367 Wrocław, Poland

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ThE EffECTS of rulE ChAngES on BASkETBAll gAME rESulTS

in ThE MEn’S EuropEAn BASkETBAll ChAMpionShipS

doi: 10.1515/humo-2015-0012

2014, vol. 15 (4), 204– 208

BEATA pluTA1_*,_{MArCin AndrzEJEwSki}1_,_{JAroSłAw lirA}2

1_{Faculty of Tourism and Recreation, University school of Physical Education, Poznań, Poland}

2_{Department of Finance and Accounting, University of Environmental and Life sciences, Poznań, Poland}

ABsTRAcT

Purpose. The aim the study was to analyze the effects of rule changes in men’s professional basketball. Univariate analysis examined game statistics, concentrating only on points scores from selected basketball games and did not include situational variables that may have affected game dynamics. Methods. Data on the results of all games played in the men’s European Basketball cham-pionships between 1935 and 2013 were collected and subjected to statistical analysis. six main rule modifications which directly affected game play were identified in chronological order. Results. The number of points scored and allowed changed significantly after 1956. The greatest changes in game scores as a result of rule modifications were after rule changes in 1956 and after 1984. Conclusions. Rule changes involve processes that modify game conditions and should be validated following reflective analysis. Key words: basketball, rules of the game, sports championships, statistical analysis

Introduction

Along with the increased popularity of basketball, multiple adjustments have been introduced to the or-ganizational framework of the game by international sports organizations [1–3]. since 1892, the rules of bas-ketball have undergone many fundamental changes, steps which have led to changes in playing dynamics.

Arias et al. [4] has proposed two types of basic sport rules. The first type of rules refer to internal logic and define the criteria that mark the relationships between a player and the rest of the team, time, spatial boundaries, and game equipment. The second are based on external logic and constitute the criteria that are nonessential to game play including the nature of a sporting event, the scoring system, team differentiators, or playing seasons. Although these elements are not directly intertwined with game ‘actions’, they can nonetheless affect game dynamics.

When considering team sports played at the competi-tive level, key elements include the specific methodology of how a score is calculated, the official rules and regu-lations determining the principles of competition, and the procedures behind team qualification, promotion, or elimination. competitive success is translated by the standing of teams according to their scores. Tables con-taining comparative data on various sports results are common in professional sports, where the main purpose of such statistics is to summarize a competitive season, sports event, the achievements of individual players, or to provide various comparative analyses in a given time

and space. A sports result in a team sport is measured directly by the points scored and lost in a game accord-ing to the formula

ST {(SE1sr1) (SE2 sr2)} so

where: ST – sports team, SEj – a given sports event,

Srj – score at the sports event, and so – standing after

the sports event.

When considering a team sport such as basketball, history shows that a number of rule modifications have been introduced. The six ‘basketball paradigms’ having the most direct impact on game play are, (1) by 1915 a) standardizing the usage of backboards and metal hoops with bottomless nets, b) setting the free-throw line 4.5 m from the backboard, c) allowing only five players from each team to be on the court at one time, d) ejecting a player after committing four fouls, e) awarding a suc-cessful shot from the court with two points, and f) re-placing the soccer ball with a special purpose-built basketball; (2) by the 1956 Melbourne Olympic Games a) the game was expanded by introducing the 3-s rule and the 30-s shot clock after gaining possession of the ball; (3) by 1984 a) introducing the three-point shot from behind a 6.25 m line, b) enlarging the basketball court, c) modifying of the 5- and 30-s rules, d) having seven team fouls in a quarter result in a ‘one-and-one’ free throw; (4) by 1994 a) having basketball matches divided into two 20-min halves or four 12-min quar-ters, b) introducing two free throws after seven team fouls in one half of a game; (5) by 2000 a) dividing a basketball game into four 10-min quarters, b) intro-ducing two free throws after four team fouls are com-mitted in a quarter, c) shortening the requirement for a team to advance the ball over the center line within

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B. Pluta, M. Andrzejewski, J. Lira, Modified rules in basketball

10 s of ball possession to 8 s, d) reducing the weight of the official basketball for women; and (6) since 2010 a) moving the three-point line back to 6.75 m, b) chang-ing the shape of the key from a trapezoid to a rectangle, c) introducing the restricted area arc with a marginally wider radius of 1.25 m, d) modifying the 24-s rule, e) in-troducing stricter penalties for flagrant fouls, especially for unsportsmanlike behavior; f) relaxing restrictions on traveling and illegally returning the ball to the back of the court.

The aim of the present study was to analyze the ef-fects of the above rule modifications on point scoring in basketball and explore any developmental tendencies. To the authors’ knowledge, no studies from the sphere of team sports theory, especially on basketball, have at-tempted to directly assess the impact of rule modifica-tions on scores. such enquiry could serve as a basis for understanding the future evolution of game outcomes.

Due to its long history (78 years), it was decided to focus on the Men’s European Basketball championships. Given the aim of the study, the following research ques-tions were posed:

1. How has the structure of point scoring in men’s professional basketball developed over the examined period?

2. Which of the changes in the rules of basketball (the six chronological ‘paradigms’) influenced the evo-lution of scoring to the greatest extent?

The study analyzed the game results from 38 Men’s European Basketball championships from 1935 to 2013, i.e. beginning with the first championship in switzer-land to the most recent event held in slovenia. Data were obtained directly from the FiBA Europe website [5] and from ströher [2]. The study protocol was approved by

the ethics committee of the Poznań University of Physi-cal Education and conducted according to the Decla-ration of Helsinki.

statistical analysis involved a summary description of all data using basic statistical methods (measures of location, spread, and shape). The arithmetic means, me-dians, interquartile ranges, and standard deviations were calculated for the number of points scored (Ps) and points allowed (PA).

significant differences between the mean ranks for Ps and PA were grouped for each rule paradigm (Rule changes 1–6) using the Kruskal–Wallis test (as a non-parametric alternative to one-way ANOVA) to allow for multiple comparisons. All statistical procedures were per-formed using statistica 9.1. software (statsoft, UsA) with the significance level set at p < 0.05.

Results

Table 1 presents the data for all 45 national teams who had participated in the 38 European Basketball cham-pionships, including those from currently defunct states. it is worth noting that 11 national teams participated in more than half of the European championships. Altogether only 34 national teams advanced to qualify in the European championships, this decrease had no effect on the standings of the top five teams. Moreover, after the division of the basketball games into halves and quarters, the ranking leaders remained the same: spain, France, Russia (divided into quarters – 16 teams) and italy, Yugoslavia, czechoslovakia (divided into halves – 30 teams). These data illustrate that the performance level of European national basketball teams remained relatively fixed over the studied timeframe.

Table 2 presents the basic descriptive statistics for points scored and allowed in all the basketball match-es played in the European Basketball championships. Table 1. Participation of national teams in the Men’s European Basketball championships (1935–2013)

No. Nat. team n % No. Nat. team n % No. Nat. team n %

1 France 36 94.7 16 Netherlands 13 34.2 31 Egypt 4 10.5

2 italy 35 92.1 17 Lithuania 12 31.6 32 Estonia 4 10.5

3 spain 29 76.3 18 Latvia 12 31.6 33 serbia 4 10.5

4 czechoslovakia 27 71.1 19 Federal Republic of Germany 12 31.6 34 Macedonia 4 10.5

5 Poland 27 71.1 20 Russia 11 28.9 35 Luxembourg 3 7.9

6 israel 27 71.1 21 croatia 11 28.9 36 Great Britain 3 7.9

7 Yugoslavia 26 68.4 22 slovenia 11 28.9 37 serbia and Montenegro 2 5.3

8 Bulgaria 24 63.2 23 sweden 11 28,9 38 Libya 2 5.3

9 Greece 24 63.2 24 Germany 10 26.3 39 Albania 2 5.3

10 Turkey 22 57.9 25 Bosnia and Herzegovina 8 21.1 40 Portugal 2 5.3

11 UssR 21 55.3 26 Austria 6 15.8 41 Georgia 2 5.3

12 Romania 17 44.7 27 Ukraine 6 15.8 42 Montenegro 2 5.3

13 Hungary 15 39.5 28 switzerland 5 13.2 43 syria 1 2.6

14 Belgium 14 36.8 29 German Democratic Republic 5 13.2 44 scotland 1 2.6

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The results were calculated for a maximum of 11 consecu-tive European championship games. Only in one case, the 2011 European championships, did the spanish na-tional team play twelve consecutive tournament matches.

A detailed comparison of points scored (Ps) and points allowed (PA) in the individual championship games showed that the vast majority of the statistical values favored comparisons made between games di-vided into quarters. This applied mainly to the arithmetic mean, marginal median, standard deviation, and coeffi-cient of variation.

The minimum number of Ps and PA in all analyzed championship games was 0 points in the 1937 cham-pionships between Latvia – Egypt (2:0) and czechoslo-vakia – Egypt (2:0). The maximum number of Ps and PA was 140 points in the 1955 championships between Poland – England (140:44). The variability in points scored and lost in all examined games was average (below 30%).

There was a noticeable dispersion of Ps and PA before the introduction of the rules encompassed in change 1. Variance between Ps and PA can be observed after the introduction of change 1. After the rules were modi-fied as per change 2, the number of points (Ps and PA) reached similar levels. Ps and PA approached values similar to the median after the introduction of change 4 and subsequent rule modifications.

The Kruskal–Wallis test revealed statistically signifi-cant differences between the successive rule changes. Multiple comparisons analysis showed no differences between changes 2 and 4, 2 and 6, 4 and 5, and 5 and 6. statistically significant differences were observed between change 2 and change 3 and change 3 and change 4 with respect to Ps in most of the championship games. These results highlight the effects of introducing the three-point shot and time restrictions on offensive play.

similar results were obtained for PA. No statisti-cally significant differences were observed between changes 2 and 4, 2 and 6, 4 and 5, and 4 and 6 (Table 3 and 4). Only the differences between change 3 and change 2 were statistically significant in the majority of the championship games. A similar relationship was found between change 3 and 4. No differences between Ps and PA were found in any of the rule modifications (Rule changes 1–6).

Discussion

The rules of basketball refer to both internal logic and external logic. Rules of internal logic may be struc-tural or functional. strucstruc-tural rules are static and de-termine the quantitative aspects of game space, time, Table 2. Descriptive statistics for points scored (Ps)

and points allowed (PA)

Total Ps PA Number of measurements 3720 3720 Minimum 0 0 Lower quartile 67.0 67.0 Marginal median 71.0 71.0 Arithmetic mean 69.9 69.9 Upper quartile 83.0 83.0 Maximum 140 140 standard deviation 20.01 20.02 coefficient of variation (%) 28.62 28.64

Table 3. Multiple comparisons; p values for points scored (Ps)

change 1 change 2 change 3 change 4 change 5 change 6

R:935,11 R:1952,1 R:2802,8 R:2130,3 R:2148,2 R:2079,5 change 1 0.000 0.000 0.000 0.000 0.000 change 2 0.000 0.000 0.084 0.009 1.000 change 3 0.000 0.000 0.000 0.000 0.000 change 4 0.000 0.084 0.000 1.000 1.000 change 5 0.000 0.009 0.000 1.000 1.000 change 6 0.000 1.000 0.000 1.000 1.000

Table 4. Multiple comparisons; p values for points allowed (PA)

change 1 change 2 change 3 change 4 change 5 change 6

R:935,93 R:1952,5 R:2806,9 R:2128,6 R:2144,6 R:2075,8 change 1 0.000 0.000 0.000 0.000 0.000 change 2 0.000 0.000 0.093 0.012 1.000 change 3 0.000 0.000 0.000 0.000 0.000 change 4 0.000 0.093 0.000 1.000 1.000 change 5 0.000 0.012 0.000 1.000 1.000 change 6 0.000 1.000 0.000 1.000 1.000

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equipment, and the number of players necessary for game play. Functional rules are qualitative in nature and determine the form and use of structural elements and indicate obligations, rights, and prohibitions con-cerning space, time, equipment, and relationships with other players. One example of a structural rule in basket-ball would be how many players per team can be found in a given area at the same time, whereas a functional rule would determine what form of body contact is permitted between players and, if exceeded, what penalties apply. Although the internal logic of a sport is not explained exclusively by its rules, they should define all the con-ditions necessary to play the game while allowing for certain freedom in athlete behavior. This variation, along with the inherent complexity of all the variables that can affect game play, makes it difficult to determine the exact implications of rule changes [4].

Most studies researching the dynamics of basketball usually are based on a singular analysis of competitive results [6–8]. Researchers analyzing basketball statistics can be divided into two groups. The first deals with in-dicators describing situational efficiency whereas the second uses various methods to assess basketball players during game play. Most of the assessment procedures use simple, one-factor models that do not consider the relationships between numerous causal variables in-fluencing the dependent variable (the score.

Earlier studies on elite basketball by Gómez et al. [9], Durković et al. [10], ibáñez et al. [11], Karipidis et al. [12], Pojskić et al. [13], Šeparović and Nuhanović [14, 15], Trninić et al. [3] attempted to determine which game-related statistical parameters best discriminated winning and losing basketball teams. Other studies searched for correlations between various game-related parameters and the win–loss record. Melnick [16] analyzed five NBA seasons to determine a relationship between team assists and team success. However, there have been very few studies on the effects of rule modifications and game out-comes. This is important as objective data are required to determine if certain game rules ought to be changed [17–21]. Rule changes directly affecting game outcomes in top-level basketball constitute an immensely compli-cated process determined by multiple factors. The iden-tification, verification, and understanding of these factors is indispensable for coaching purposes and requires the application of complex analytical research methods [9, 11, 12, 15, 22, 23].

Performance analyses in basketball is a fundamen-tal tool for coaches, allowing them to obtain valid and reliable information on their team and competitors. This information can be used to not only identify the most valuable players but also determine the importance of specific roles as well as evaluate the performance of starting players and substitutes [24, 25]. such analysis can determine how each player contributes to team per-formance [26] as well as assess the impact of rule changes on game results [27].

The aim of the present study was to determine the effects of rule changes on scoring by examining the re-sults in the European Basketball championships over the last decades. Rule changes modify the game conditions with a certain goal in mind. For example, in 2000 the international Basketball Federation (FiBA) changed the rules of basketball in Europe to speed up offensive play with hopes of increasing viewership and attracting more sponsors. This was performed by reducing backcourt time from 10 to 8 s and the shot clock from 30 to 24 s. These changes in combination with the continuous im-provement of defensive tactics significantly altered of-fensive play.

However, the results of the present study show that successive changes in official rules have not always had a direct impact on sports outcomes. The number of points scores and points allowed changed significantly as a con-sequence of such modifications starting from 1956. The largest effect on the pace of a basketball game, and indi-rectly on the number of scored points, was a decrease in shot time and rules on advancing the ball over the center line.

The greatest changes in game scores were noted fol-lowing the introduction of changes 2 and 3. in particu-lar, change 3 decidedly increased the number of scored and allowed points in the matches under study. similar observations were also made by Gomez et al. [27] and ibáñez et al. [11]. This suggests a quickened game pace [28] and indicative of better physical parameters per-mitting more intensive defensive play, more physical contact, and game play based on defensive rebounds to gain ball possession and the use of fouls to block offensive.

Therefore, it is possible to distinguish two explana-tions for rule changes in basketball. The first is the need to modify the accepted threshold of poor sporting be-havior. The second is the need to modify game dynam-ics and motor demands, allowing the game to improve over time. such changes help smooth out game play and facilitate referring and resolve in-game contentions. Rule changes also help improve the game’s popularity among spectators. Future changes in basketball may involve creased time restrictions to enhance viewership by in-creased game dynamics. Other changes could include moving the three-point line by a few centimeters, requir-ing a greater development of player techniques and skills.

Conclusions

The present study is novel as no other studies in the literature have analyzed the effects of rule modifi-cations in basketball on game results. since the data set used in the study is relatively small, any conclu-sions can be considered arbitrary and demand addi-tional examination. However, future research should concentrate on data originating from teams of a simi-lar competitive level.

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3. Trninić s., Dizdar D., Lukšić E., Differences between winning and defeated top quality basketball teams in final tournaments of European club championship. Coll An-tropol, 2002, 26 (2), 521–531.

4. Arias J.L., Argudo F.M., Alonso J.i., Review of rule modi-fication in sport. J Sports Sci Med, 2011, 10 (1), 1–8. 5. Available from http://www.fiba.com

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Correspondence address Beata Pluta

Wydział Turystyki i Rekreacji Akademia Wychowania Fizycznego ul. Królowej Jadwigi 27/39

61-871 Poznań, Poland